Packages for dispensing fluent materials by employing self-closing discharge nozzles are known in the art. For example, U.S. Pat. No. 2,071,657 issued to Richardson on February 23, 1937 discloses a collapsible tube employing a self-closing nozzle employing a pair of self-closing jaws. The jaws, which open to form an orifice in response to pressure of the fluent material, close off the discharge end of the tube when the pressure of the fluent material inside the container is relieved.
Another exemplary structure of this type is shown in U.S. Pat. No. 3,506,163 issued to Rauh et al. on April 14, 1970. The patent to Rauh et al. discloses a collapsible container for a flowable material. The container includes a normally closed spout which opens automatically in response to a pressure increase inside the container. At the end of any given product dispensing cycle, the spout automatically assumes its closed position, thus maintaining the flowable material within the container out of contact with the atmosphere and preventing the container from expanding back to its initial volume. The container of Rauh et al. is progressively collapsed as the flowable material is dispensed.
A practical difficulty experienced with structures of the aforementioned type is that they will dispense fluent material in response to an increase in pressure whenever external forces are applied to the container. Accordingly, some type of mechanical closure must be utilized during the filling, handling and shipping of such packages to avoid unwanted material discharge during these necessary operations. Furthermore, in the event the mechanical closure mechanism utilized to ensure a seal during the filling, handling and shipping stages becomes lost or discarded after the user places the package in service, the package cannot practically be restored to a leak-proof condition. Thus packages of the aforementioned type may not practically be employed in a travel bag or the like once the closure mechanism has become lost or separated therefrom.
Dispensing packages, particularly dispensing closures, having integral valve means which are not responsive to pressure of the package contents are also generally known in the art. The valve means in such closures often comprises a rotatable turrent which in a first position prevents discharge of the package contents regardless of the pressure to which the package is subjected and which in a second position freely permits discharge of the package contents in response to increased pressure of the package contents.
Typical of such dispensing closures are the structures shown in U.S. Pat. No. 3,568,895 issued to Porter on March 9, 1971; U.S. Pat. No. 3,874,562 issued to Hazard on April 1, 1975; U.S. Pat. No. 4,282,991 issued to Hazard on August 11, 1981; and U.S. Pat. No. 4,440,327 issued to Dark on April 3, 1984. The aforementioned references disclose various forms of turrets which are rotatable in a vertical plane.
Dispensing closures having turret mechanisms which are rotatable in a horizontal plane are also generally known. Structures of the type disclosed in U.S. Pat. No. 2,880,914 issued to Lerner et al. on April 7, 1959 and U.S. Pat. No. 3,162,333 issued to Davidson on December 22, 1964 are typical of structures employing such horizontally rotatable turrets.
While structures employing multi-position valves, particularly valves of the turret type do permit easier filling, handling and shipping of fluent materials, they are nonetheless prone to problems once the user places them in service. In particular, spillage of the fluent material may occur if the package is tipped over or dropped while the valve is in the "open" position. Furthermore, if the user forgets to close the valve after dispensing fluent material from the package, dryout and clogging of the valve passageways and the material inside the package is likely to occur. Since there is no positive cutoff of product when the dispensing cycle ceases, dripping of fluent material from the package is also likely to occur after the dispensing cycle has been completed.